Wood fiberboard

ABSTRACT

A wood fiberboard, in particular floor panel including an HDF support board with a top side and an underside, the top side having a decoration, preferably a wood or tile decoration, is distinguished in that the decoration is printed directly onto the top side of the support board and is covered by at least one layer of a transparent synthetic resin.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a wood fiberboard, in particular a floor panel,comprising an HDF support board with a top side and an underside, thetop side having a decoration, preferably a wood or tile decoration, andto a process for producing such a wood fiberboard.

2. Background Description

Floor panels with a wood-fiber support board are usually referred to aslaminate panels and have been commercially available for many years as asubstitute for parquet flooring. The desired decoration (parquet,woodgrain, tiles, etc.) is printed onto a paper web, which is thencoated with resin and rolled onto a roll. At the floor manufacturer's,the decorative web which has been prefabricated in this way ispositioned on the support board and pressed. As a result of theoperations of printing the decoration on to the paper web, ofsubsequently sealing the paper web with synthetic resin and of thenconnecting the decorative layer to the support board by pressure andtemperature, the dimensions of the paper web change. According to theperson skilled in the art, the paper grows. The paper grows both inlength (increase in length) and in width (increase in width). If thisdecorative board is then to be cut to size to form individual panels,the increase in length and width has to be taken into account because,otherwise, the decoration would be distributed unevenly on theindividual panels. This would result in the floor made up of an unevenlydistributed decorative layer having the decorations offset along theconnecting edges of the panels. Even if the decorations are only offsetby a few millimeters, they are obvious to the observer, this having anadverse effect on the esthetic appearance and thus reducing the qualityof the covered floor.

In order for it to be possible to carry out production with appropriatequality, the paper growth has to be detected and the saw which saws thepanels from the support board has to be set correspondingly. Manualsetting is very time-consuming. DE 100 19 054 C1 describes a processwhich is intended for cutting panels to size from a support board and bymeans of which the saw can be automatically adapted to the paper growth.Cameras are necessary for this purpose, the cameras determining theactual position of defined points of the decoration. The actual positionis then compared with the desired position and the deviation of thewidth or length dimension is determined, with the result that the sawcan be set correspondingly.

In order to optimize the cutting, fairly high outlay is thus necessary,and this increases the cost of the production of high-grade panels. Inorder further to match the appearance of the laminate panel to theappearance of a natural-wood panel, a relief-containing female die maybe provided in the press in which the decorative layer is pressed withthe support board, a relief which corresponds to the woodgrain beingstamped into the synthetic resin layer by means of said die. Since thepaper growth is not reproducible, it is not possible to make the reliefcorrespond fully with the decoration. The joints of a tiled surfacecannot be stamped into the surface of the synthetic-resin layer sincedeviations would be immediately visible here.

SUMMARY OF THE INVENTION

Taking this problem as the departure point, the intention is to improvethe wood fiberboard described in the introduction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an aspect of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The problems is solved, in the case of a wood fiberboard 1 of thegeneric type, in that the decoration 2 is printed directly on top thetop surface of the support board and is covered by at least one layer ofa transparent synthetic resin 3, preferably melamine resin or urearesin.

In addition, it is also possible for the decoration to be printed ontothe underside of the support board and to be covered by at least onelayer of a transparent synthetic resin. If appropriate, the undersideand/or the top side of the support board may be provided with a reliefcorresponding to the decoration, this relief being pressed into thesynthetic-resin layer.

By virtue of this configuration, the paper layer is eliminated. Duringpressing of the synthetic-resin layer, the decoration changes neither inlength nor in width. The saw which is subsequently used to cut panels tosize, may be preset. It is possible to stamp into the synthetic-resinlayer of the board designed according to the invention even the mostintricate reliefs, which correspond precisely with the decoration. Theproduction costs of high-quality panels are considerably reduced. Afurther saving is achieved in that the paper layer is dispensed with.

The decoration is preferably covered by two layers of a synthetic resin,the layer which is applied directly to the decoration having corundumparticles for increasing the abrasion resistance.

A process for producing the wood fiberboard according to the inventionis distinguished by the following steps:

-   a) a decoration, preferably a wood or tile decoration, is printed    onto one or two sides of the board;-   b) a screen roller is used to spread one or more synthetic-resin    layers on the side with the decoration (top side) and the sides    located opposite the latter (underside);-   c) the synthetic-resin layers are pressed with the board in a known    manner in a short-cycle-press.

The absence of paper layers prevents the resulting boards from warping,which could be produced by the inherent tensile force of the papers.Short pressing times may be realized as a result of the thin layers.

Instead of HDF (High Density Fiberboard), it is also possible for thesupport board to be made of MDF (Medium Density Fiberboard) or also aconventional chipboard with a correspondingly finely distributed coverlayer, from which, for example, smaller panels used for furnitureconstruction can then be sawn.

Boards which are produced in this way may also be used as floors in thatthey may be sawn to form panels in a format appropriate to thedecoration.

1. A wood fiberboard, composed of a panel comprising a support boardwith a top side and an underside, the top side having a decoration, of awood or tile decoration, wherein the decoration is printed onto the topside of the support board and is covered by at least one layer of atransparent synthetic resin, and the support board is made of one ofHDF, MDF, and chipboard, and wherein the top side has a reliefcorresponding to the decoration.
 2. The wood fiberboard, according toclaim 1, wherein the decoration is printed on to the underside of thesupport board.
 3. The wood fiberboard, according to claim 1, wherein thedecoration is covered by two layers of a synthetic resin, the layerwhich is applied directly to the decoration having corundum particlesfor increasing the abrasion resistance.
 4. The wood fiberboard,according to claim 1, wherein the underside also has a reliefcorresponding to the decoration.
 5. The wood fiberboard, according toclaim 1, wherein the decoration is covered by two layers of a syntheticresin, the layer which is applied directly to the decoration havingcorundum particles for increasing the abrasion resistance.
 6. The woodfiberboard, according to claim 1, wherein the decoration is printeddirectly on the top side of the support board.
 7. The wood fiberboard,according to claim 1, wherein the support board is composed of HDF.
 8. Awood fiberboard, composed of a panel comprising a support board with atop side and an underside, the top side having a decoration, of a woodor tile decoration, wherein the decoration is printed directly onto thetop side of the support board and is covered by a paper free layer of atransparent synthetic resin, and the support board is made of one ofHDF, MDF, and chipboard.
 9. The wood fiberboard of claim 8, wherein thesupport board is composed of HDF.